This invention generally relates to the field of mobile equipment for digging trenches.
In construction and landscaping work it is frequently necessary to dig trenches with walls at angles which vary from the vertical, and many times it is desirable to form a trench wherein each of the side walls thereof are at different angles from the vertical. While there are many prior art devices form trenches with angled side walls, many are inconvenient to use and, none provide any capability of varying the angle to suit the particular needs of a situation. Typical prior art devices for forming trenches with inclined side walls are shown in the following references:
U.S. Pat. No. 2,480,656 (Jenne), PA1 U.S. Pat. No. 2,972,425 (Anderson, et al.), PA1 U.S. Pat. No. 3,003,264 (Shore), PA1 U.S. Pat. No. 3,792,539 (Clark). PA1 U.S. Pat. No. 2,261,874 (Cundiff), PA1 U.S. Pat. No. 2,556,592 (Markkula), PA1 U.S. Pat. No. 2,662,311 (Chattin), PA1 U.S. Pat. No. 2,673,409 (Briscoe), PA1 U.S. Pat. No. 2,856,709 (Brockly). PA1 U.S. Pat. No. 3,526,047 (Roessler, et al.)
In the Jenne, Shore and Clark references the side walls of the trench are formed by a blade or wing which are attached to the front or leading edge of a backhoe or drag line bucket. In the Anderson, et al. reference the bucket is provided with fixed, angled sides which form the sloping walls of a trench. None of the described devices are provided with means to adjust the angle of the side plate of the bucket.
Other references relating to backhoes or drag line buckets for forming trenches which may be of interest are U.S. Pat. No. 3,089,261 (Flath) and U.S. Pat. No. 3,286,377 (Long) which describe wing-like devices attached to the vertical side walls of the bucket to change the cross-sectional shape of the trench. However, no attempt is made to change the angle of the side wall.
For other prior art devices showing a scraping type action for the removal of dirt and the like, reference is made to the following references:
These references primarily are directed to devices having blades which scrape or plow the ground. They do not involve a trench forming type of bucket.
From the above, it is clear that the need remains for a bucket for a trenching device which can form trenches with walls of varying slope and, particularly, a device which can readily vary the slope to meet the particular job requirements without significant modifications to the bucket or the need to replace buckets for particular angled walls. The present invention satisfies this need.